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A battery bridge for an electronic device, preferably for an electronic
implant, has an electrically conductive first contact element, an
electrically conductive second contact element and an insulator. The
first contact element and the second contact element comprise a weldable
material. In a first state of the battery bridge, the first contact
element is distanced from the second contact element via a predefined air
gap and the first contact element is electrically insulated from the
second contact element by the air gap and the insulator. The battery
bridge is formed in such a way that it can be transferred, by welding the
first contact element and the second contact element together, into a
second state, in which the air gap between the first contact element and
the second contact element is closed electrically conductively, at least
in part. A method for activating such an electronic device is also
disclosed.

1. A battery bridge for an electronic device, preferably, for an
electronic implant, comprising: an electrically conductive first contact
element; an electrically conductive second contact element; and an
insulator, wherein the first contact element and the second contact
element comprise a weldable material, wherein, in a first state of the
battery bridge, the first contact element is distanced from the second
contact element via a predefined air gap and the first contact element is
electrically insulated from the second contact element by the air gap and
the insulator, wherein the battery bridge is configured in such a way
that it can be transferred, by welding the first contact element and the
second contact element to one another, into a second state, in which the
air gap between the first contact element and the second contact element
is closed electrically conductively, at least in part.

2. The battery bridge according to claim 1, wherein the insulator is
substantially annular, the first contact element is substantially
U-shaped or hollow cylindrical in cross-section, and the second contact
element is substantially cylindrical, wherein the annular insulator is
arranged between the first contact element and the second contact
element.

3. The battery bridge according to claim 2, wherein the second contact
element is arranged within an inner opening of the first contact element,
which opening is preferably continuous.

4. The battery bridge according to claim 2, wherein the second contact
element has a sloped portion, which shields an electric circuit arranged
beneath the battery bridge from a laser light used for welding.

5. The battery bridge according to claim 2, wherein the first contact
element and/or the second contact element has, in a portion serving for
connection to the electric circuit, a coating which improves
solderability.

6. The battery bridge according to claim 2, wherein the second contact
element, in the region of an upper end face of the first contact element,
in which region the welding is performed, protrudes beyond this upper end
face.

7. The battery bridge according to claim 1, wherein the insulator is
formed as a ceramic substrate and the first contact element is formed as
a first metal foil and the second contact element is formed as a second
metal foil, wherein the first contact element and the second contact
element are arranged on the insulator at a distance corresponding to the
width of the air gap.

8. The battery bridge according to claim 1, wherein the first contact
element has a first shape and the second contact element has a second
shape, which is complementary to the first shape, wherein the air gap is
formed at the opposing faces of the first shape and the second shape and
in a region is filled out by the insulator, which is formed for example
as an adhesive film.

9. The battery bridge according to claim 1, wherein the air gap has a
width ranging from 10 .mu.m to 100 .mu.m.

10. The battery bridge according to claim 1, wherein the air gap has a
width ranging from 30 .mu.m to 80 .mu.m.

11. A method for activating an electronic device, preferably an
electronic implant, comprising an electric circuit by means of a battery
bridge according to claim 1, comprising the following steps: positioning
and fastening the battery bridge in the first state on the electric
circuit and producing an electrically conductive connection between the
first contact element and a first conductive track and between the second
contact element and a second conductive track of the electric circuit;
connecting the electric circuit to a voltage source and/or a capacitor
and/or a dump resistor; powering up the electric circuit via at least two
predefined test points; and transferring the battery bridge into the
second state by at least partially welding the first contact element and
the second contact element to one another, in such a way that the air gap
is electrically conductively closed, at least in part.

12. The method according to claim 11, wherein a butt seam welding method
or a fillet welding method or a through-welding method is used for
welding.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This patent application claims the benefit of and priority to
co-pending German Patent Application No. DE 10 2016 101 620.9, filed on
Jan. 29, 2016 in the German Patent Office, which is hereby incorporated
by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates to a battery bridge for an electronic
device, preferably for an electronic implant and also to a method for
activating an electronic device of this type comprising an electric
circuit.

BACKGROUND

[0003] A battery bridge is understood to mean the contact of an electric
circuit of an electronic device that remains open last. If the open
contact of the battery bridge is closed following assembly and testing of
the electronic device, the device is thus activated, i.e., the electric
circuit forming the basis of the device is permanently closed.

[0004] With regard to an electronic implant, correct activation is of
course of particular importance, since lasting fault-free functioning of
the implant must be ensured. By way of example, cardiac pacemakers,
cardioverter defibrillators, electronic drug delivery devices, or
implantable sensors (biomonitors) are currently used as electronic
implants.

[0005] Due to the requirement that an electric circuit for electronic
devices of this type should take up as little space as possible, said
circuit is currently often produced by means of SMT (surface mounting
technology). In the case of surface mounting technology, components are
soldered directly onto a printed circuit board by means of solderable
connection faces.

[0006] In order to activate an electronic device, a soldering method was
used previously, for example, in which tin is applied by means of a
soldering iron and closes the circuit between two adjacent soldering
faces on the printed circuit board (PC board or PCB). The disadvantage of
this conventional solution lies in the fact that soldering methods
nowadays cannot be reliably automated in respect of the small structures
as can be provided on highly compact circuits, since the soldering
process is influenced by the solder amount, the soldering temperature,
the fluxing agent, the cleanliness of the surfaces, and the like.

[0007] It is also known to keep a contact of the battery strip insulated
by means of a temporary insulator until activation. Once the electronic
device is finished, the contacts having been welded, the device is
powered up via test points. Following successful power-up, the temporary
insulator is manually removed; the battery strip, which has not yet been
welded on, is manually held down and manually welded on by means of one
to two weld points. This method has the disadvantage that the circuit
must be activated by a complex power-up device, wherein a connection lug
of the battery always has to be insulated via a temporary insulator. An
accidental contacting of the strip (bounce of the contact) and therefore
accidental initialization should be avoided as a result of this measure.
It is also disadvantageous that in this method, following successful
initialization of the circuit, the temporary insulator is manually
removed from the battery connection strip, the strip is placed by means
of tweezers on the circuit, and then must be welded on to the weld path.
This complex manual process step is time-consuming and requires fine
motor skills. It cannot be automated from the viewpoint of
cost-effectiveness. In addition, additional material has to be provided,
fed and positioned for the temporary insulator. The same is true for the
connection strip.

[0008] An alternative solution lies in closing the circuit by means of a
bonding method. For this purpose, material (for example, aluminum
strip/wire) has to be fed, and the strip ends have to be welded on by
means of friction welding or laser welding. The bonding method
presupposes an already fixed internal structure of the electric circuit,
for example, by gluing, on account of the high forces that occur as the
strip is held down and welded on (resistance welding). However, this is
problematic for electronic implants, since no adhesives can be used, so
as to avoid a high expenditure of time for the curing of an adhesive and
also adhesive evaporation, which can have a negative effect on the
electronic behavior of the device.

[0009] A further alternative possible embodiment for a battery bridge
could consist in closing the circuit by means of a plug-in contact.
However, for electronic implants there is the requirement that the
electronic circuit must operate reliably over the entire service life of
the implant, that is to say up to 10 years. The material fatigue of the
springs or contact resistances, which change over time, however,
constitute a risk in respect of the product reliability. The use of
plug-in contacts/spring contacts for electronic devices such as
electronic implants therefore is not recommended.

[0010] The present invention is directed toward overcoming one or more of
the above-mentioned problems.

SUMMARY

[0011] An object of the present invention thus lies in creating a battery
bridge with which an electric circuit can be reliably activated in a
simple, automatable manner. In respect of the method, an object is to
specify a method which enables an activation of an electronic device in a
simple and economical way.

[0012] At least the above object(s) is achieved by a battery bridge which
has an electrically conductive first contact element, an electrically
conductive second contact element, and an insulator, wherein the first
contact element and the second contact element comprise a solderable
material, wherein, in a first ("open") state of the battery bridge, the
first contact element is distanced from the second contact element by a
predefined air gap and the first contact element is electrically
insulated from the second contact element by the air gap and the
insulator, wherein the battery bridge is configured in such a way that it
can be transferred, by welding the first contact element and the second
contact element to one another, into a second ("closed") state, in which
the air gap between the first contact element and the second contact
element is permanently closed electrically conductively, at least in
part.

[0013] By means of the battery bridge according to the present invention,
in the second (closed) state, an electric circuit is closed and,
therefore, the device comprising the circuit is activated. For this
purpose, the material of the first contact element and the material of
the second contact element are fused together in the region of the air
gap by means of welding, such that on the one hand the weld seam or weld
spot of the air gap is closed and on the other hand an electrically
conductive connection is established between the first contact element
and the second contact element.

[0014] The battery bridge according to the present invention must consist
of weldable material, at least in the area of the contact elements in
which the welding is performed by way of example, the first contact
element and the second contact element can be made at least in part of at
least one material of the group containing nickel, copper, copper-nickel
alloys, copper, niobium, tanatalum, molybdenum, stainless steel, platinum
alloys, palladium alloys, and titanium.

[0015] The air gap preferably has a width ranging from 10 .mu.m to 100
.mu.m, particularly preferably ranging from 30 .mu.m to 80 .mu.m. An air
gap of this type on the one hand has the necessary insulating property in
the first (open) state and on the other hand can be reliably closed
electrically conductively by means of laser welding in order to produce
the second (closed) state. In the first (open) state, the electronic
device is not activated.

[0016] The insulator insulates the first contact element and the second
contact element electrically from one another. However, the insulator
also serves for the mechanical fastening of the first contact element and
the second contact element. For this purpose, the insulator is preferably
arranged either between the first contact element and the second contact
element and is connected thereto, or the first contact element and the
second contact element are arranged on the insulator and are fastened
thereto.

[0017] The battery bridge according to the invention is characterized in
that it can be economically produced and, by means of the welding
process, also enables an automated activation of the electronic device.
With the use of a battery bridge according to the present invention, the
activation/initialization can therefore be performed in a narrow,
automated manufacturing sequence.

[0018] It is also advantageous when the insulator is substantially
annular, the first contact element is substantially U-shaped or
hollow-cylindrical in cross-section, and the second contact element is
substantially cylindrical, wherein the annular insulator is arranged
between the first contact element and the second contact element. The
U-shaped or hollow-cylindrical first contact element is also referred to
as a cap, and the second cylindrical contact element is also referred to
as a plunger. A rotationally symmetrical design of the components of this
type means that these are automatically centered and the small insulation
distance can thus be provided reliably along the entire welding edge. The
insulator holds the electrically conductive, preferably metal, contact
elements of the battery bridge in position and ensures the predefined air
gap, which provides the insulation of the contact elements from one
another. Accidental contact between the first contact element and the
second contact element can thus be avoided. An arrangement of the
components that is particularly advantageous in respect of the spatial
requirement is given in that the second contact element is arranged,
particularly preferably in a press fit, within an inner opening of the
first contact element, which opening is preferably continuous.

[0019] It is also advantageous, in particular in respect of the
above-explained rotationally symmetrical exemplary embodiment, when the
first contact element and/or the second contact element are produced from
a metal material by means of a cold forming or stamping process. The
insulator can be embodied for example as a plastics injection-molded
part, for example, comprising a material of the group containing POM
(polyoxymethylene), PEEK (polyether ether ketone), LCP (liquid-crystal
polymer), and PBT (polybutylene terephthalate), or as a film comprising a
material of the group containing PEEK, polyimide, LCP and polyarylate.

[0020] In a further preferred exemplary embodiment the second contact
element, preferably also the first contact element, has a sloped portion,
which shields a laser light used for welding from an electric circuit,
for example, a printed circuit board, arranged beneath the battery
bridge. The sloped portion is characterized in that, in this portion, in
particular with a rotationally symmetrical design of the first contact
element or of the second contact element, the diameter of the
corresponding contact element changes from a smaller diameter to a larger
diameter, such that the contact element forms a sloping edge. Due to this
sloped portion, the laser light is deflected and reflected in a direction
away from an electric circuit disposed therebeneath, such that damage to
the circuit caused by the welding of the first contact element to the
second contact element is avoided.

[0021] In a further preferred embodiment, the first contact element and/or
the second contact element have/has, in a portion serving for connection
to the electric circuit, a coating which improves solderability and which
for example contains gold (e.g., ENIG (electroless nickel immersion
gold)) and/or palladium. As a result, the soldered connection of the
battery bridge to corresponding contact faces of conductive tracks of a
printed circuit board, for example, during surface mounting, is improved.

[0022] It is also advantageous when the second contact element, in the
region of an upper end face of the first contact element, in which region
the welding is performed, protrudes beyond this upper end face. Due to
the shaping of the battery bridge according to the present invention, an
improved welding in order to close the air gap between the first contact
element and the second contact element is achieved, for example, by means
of fillet welding. The produced weld seam can be easily examined in
respect of its quality, i.e., the establishment of an electrically
conductive connection between the first contact element and the second
contact element.

[0023] In an alternative embodiment, compared to the U-shaped or
cylindrical design of the first contact element and of the second contact
element, the first contact element is formed as a first metal foil and
the second contact element is formed as a second metal foil. The
insulator is formed by a ceramic substrate. The first contact element and
the second contact element are also arranged adjacently on the insulator
at a distance corresponding to the width of the air gap. This exemplary
embodiment can be produced particularly easily and economically, for
example, by means of thick-film technology, wherein the air gap is
preferably produced in that a continuous metal film resting on the
ceramic substrate is separated, for example, by means of laser cutting.
At the same time, the second metal foil distanced from the first metal
foil is formed as a result. Electrically conductive contact with an
electric circuit (printed circuit board, PCB) arranged therebeneath and
comprising the first contact element or the second contact element is
established in this embodiment by means of a soldering coating arranged
laterally on the battery bridge, which coating spans, in a U-shaped
manner, the ceramic substrate and preferably additionally the first
contact element or second contact element resting thereon. A nickel
intermediate layer is preferably arranged between the first contact
element and the second contact element or the insulator and the soldering
coating and serves to produce the solderability and wettability with soft
solder.

[0024] The weldable metal foil of the first contact element and the second
contact element can, for example, comprise at least one material of the
group containing nickel, copper, copper-nickel alloys, tanatalum,
niobium, molybdenum, titanium and stainless steel. The production is
performed in a thick-film method, similarly to an industrially produced
thick-film resistor (TFR). On account of the production by means of
thick-film technology, a battery bridge according to this exemplary
embodiment can be produced very efficiently and economically. The metal
foil of the first contact element and/or of the second contact element by
way of example has a layer thickness ranging from 200 .mu.m to 600 .mu.m.
The dimensions of a battery bridge produced in accordance with this
exemplary embodiment can be, for example, 2 mm.times.1.25 mm. This
battery bridge according to the present invention is therefore
characterized in addition to the above-mentioned properties by small
dimensions and therefore by a small area requirement.

[0025] In a further alternative exemplary embodiment, the first contact
element has a first shape and the second contact element has a second
shape, which is complementary to the first shape, wherein the air gap is
formed at or between the opposing faces of the first shape and the second
shape and in a region is filled out by the insulator, which, for example,
is formed as an adhesive film (for example, in the form of an acrylate
adhesive). The first contact element and the second contact element are
weldable metal components, for example, comprising a material of the
group containing nickel, a copper-nickel alloy, and stainless steel. As
complementary shape, an L-shape (in cross-section) can be used, for
example. Other shapes, for example complementary wave shapes, are also
conceivable.

[0026] The insulator formed as adhesive film and arranged in the region of
part of the air gap between the two complementary shapes fixes the air
gap between the first contact element and the second contact element.
Since the first contact element and the second contact element extend as
far as the underside of the battery bridge, they can each be directly
connected to a contact face of an electric circuit (e.g., printed circuit
board) arranged therebeneath. A battery bridge of this type measures, for
example, 2 mm.times.1.25 mm in size and therefore has a small spatial
requirement. The complementary shapes of the first and the second contact
element of this exemplary embodiment can be produced by cold forming
(e.g., stamping, embossing) or by material removal (e.g., milling, water
jet cutting, etching).

[0027] A battery bridge of this type can preferably be provided with a
housing produced by means of plastics injection molding. Here, however,
the upper side of the battery bridge comprising the first contact
element, the second contact element, and the air gap arranged
therebetween is free, such that the air gap is accessible for welding at
the time of activation of the electric circuit. The underside of the
contact elements is also not covered by the housing, since this serves to
establish contact with the electric circuit.

[0028] At least the above object(s) is also achieved by a method for
activating an electronic device, preferably an electronic implant,
comprising an electric circuit by means of an above-described battery
bridge, said method having the following steps:

[0029] positioning and fastening the battery bridge in the first (open)
state on the electric circuit and producing an electrically conductive
connection between the first contact element and a first conductive track
and also between the second contact element and a second conductive track
of the electric circuit, wherein the connection to the first conductive
track and/or the second conductive track is established preferably via a
corresponding contact face,

[0030] connecting the electric circuit to a voltage source and/or a
capacitor and/or a dump resistor,

[0031] powering up the electric circuit via at least two predefined test
points, and

[0032] transferring the battery bridge into the second (closed) state by
at least partial welding of the first contact element and the second
contact element to one another, in such a way that the air gap is
permanently closed electrically conductively, at least in part.

[0033] The method according to the present invention includes an
automatable welding process and, therefore, a greater process
reliability. The run-through time for the power-up can thus be reduced.
In the method according to the present invention, simpler manufacturing
aids, for example, merely a workpiece carrier, can also be used, and no
additional parts are fed or carried away, such that the course of the
manufacturing process can be provided in a straightforward manner. The
battery bridge according to the present invention or the method according
to the present invention can therefore be used in particular in the
production of electronic implants in the field of medical technology, in
particular in cardiac pacemaker/ICD/biomonitor production.

[0034] A butt seam welding method, a fillet welding method or a
through-welding method is preferably used for welding, depending on the
shape of the air gap or of the first contact element and the second
contact element.

[0035] Further embodiments, objectives, features, advantages and possible
applications of the present invention will become clear from the
following description of exemplary embodiments with reference to the
drawings. Here, all features described and/or illustrated in the drawings
form the subject matter of the present invention, independently or in any
combination, even regardless of their summary in the claims and the
dependency references of the claims.

DESCRIPTION OF THE DRAWINGS

[0036] This invention is explained in detail below on the basis of some
sample embodiments. The figures are as follows:

[0037] FIG. 1 schematically shows a first exemplary embodiment of a
battery bridge according to the present invention in the first state
connected to a printed circuit board, in a perspective view from the
side,

[0038] FIG. 2 schematically shows the arrangement according to FIG. 1 in
cross-section,

[0039] FIG. 3 schematically shows the exemplary embodiment according to
FIG. 1 in an exploded illustration, in a view from the side,

[0040] FIG. 4 schematically shows the arrangement according to FIG. 3 in
cross-section,

[0041] FIGS. 5-9 schematically show a first exemplary embodiment of a
method according to the present invention for activating an electronic
device comprising a battery bridge according to FIG. 1 in a number of
steps, wherein a perspective view from the side is shown in FIGS. 5-7 and
9 and a sectional illustration is shown in FIG. 8,

[0042] FIG. 10 schematically shows the arrangement according to FIG. 1 in
cross-section,

[0043] FIG. 11 schematically shows the arrangement according to FIG. 10 in
a second state of the battery bridge,

[0044] FIG. 12 schematically shows a second exemplary embodiment of a
battery bridge according to the present invention in a first state, in a
perspective view from the side,

[0045] FIG. 13 schematically shows the exemplary embodiment according to
FIG. 12 in cross-section during the welding,

[0046] FIG. 14 schematically shows a third exemplary embodiment of a
battery bridge according to the present invention in a first state, in a
perspective view from the side,

[0047] FIG. 15 schematically shows the exemplary embodiment according to
FIG. 14 in cross-section during the welding,

[0048] FIG. 16 schematically shows a fourth exemplary embodiment of a
battery bridge according to the present invention in a perspective view
from the side during the welding,

[0049] FIG. 17 schematically shows a fifth exemplary embodiment of a
battery bridge according to the present invention in a first state, in a
perspective view from the side, connected to a printed circuit board,

[0050] FIG. 18 schematically shows the arrangement according to FIG. 17 in
cross-section,

[0051] FIG. 19 schematically shows the arrangement according to FIG. 18 in
a second state of the battery bridge,

[0052] FIGS. 20-23 schematically show a second exemplary embodiment of a
method according to the present invention for activating an electronic
device comprising a battery bridge according to FIG. 17 in a number of
steps, in each case in a perspective view from the side,

[0053] FIG. 24 schematically shows a sixth exemplary embodiment of a
battery bridge according to the present invention in a first state, in a
perspective view from the side, connected to a printed circuit board,

[0054] FIG. 25 schematically shows the arrangement according to FIG. 24 in
a second state of the battery bridge,

[0055] FIG. 26 schematically shows a seventh exemplary embodiment of a
battery bridge according to the present invention in a first state, in a
perspective view from the side,

[0056] FIG. 27 schematically shows the arrangement according to FIG. 26 in
a cross-section,

[0057] FIG. 28 schematically shows the arrangement according to FIG. 26 in
a second state, in a partial transparent illustration of the battery
bridge, and

[0058] FIG. 29 schematically shows an electronic device in the form of a
cardiac pacemaker in cross-section including a circuit diagram with a
battery bridge according to the present invention according to FIG. 1 in
the first state.

DETAILED DESCRIPTION

[0059] The first exemplary embodiment of a battery bridge 1 according to
the present invention illustrated in FIGS. 1-11 has a substantially
weldable hollow-cylindrical cap (first contact element) 11 and a
weldable, substantially cylindrical plunger (second contact element) 12.
A ring 13 (insulator) is also provided and is arranged between the cap 11
and the plunger 12. The plunger 12 and the ring 13 are arranged within
the continuous opening 15 of the cap 11. The ring 13 provides a
concentric positioning of the plunger 12 and cap 11 relative to one
another, in such a way that an air gap 18 is formed therebetween. That
air gap by way of example has a width of approximately 50 .mu.m. In the
first (open) state of the battery bridge illustrated in FIGS. 1-2, 5-6
and 10, the metal cap 11 and the metal plunger 12 are electrically
insulated from one another by means of the electrically insulating ring
13 and the air gap 18. The plunger 12 has the same height as the cap 11,
such that the upper end face 16 of the cap 11 and the upper end face 34
of the plunger 12 are flush with one another.

[0060] The plunger 12 has, in a central region, a sloped portion 19
relative to the height of the battery bridge 1 or the plunger 12, in
which sloped portion the diameter of the plunger 12 changes from a
smaller diameter to a larger diameter. The change in diameter lies, for
example, in a range between 100 .mu.m and 500 .mu.m. A transition region
or "kink" is thus formed to a certain extent in the plunger 12 in the
sloped portion 19 and, as illustrated in FIG. 8, shields an electric
circuit disposed therebeneath--here in the form of a printed circuit
board 25--from the laser light of a laser beam 40, which is used for
welding. Accordingly, the cap 11 can also have a sloped portion 20, and
the ring 13 can have a sloped portion 21, wherein this portion 21 is
arranged on the ring 13, as shown in FIG. 4, in the region of the upper
side of the ring 13. This is provided on account of the arrangement of
the ring 13 within the cap 11.

[0061] The method according to the present invention for activating an
electronic device, for example, an electronic implant, by means of the
battery bridge 1 according to FIG. 1 and a cardiac pacemaker 400
according to FIG. 29 as an example of an electronic implant will be
explained hereinafter with reference to FIGS. 5-9 and 29.

[0062] The cardiac pacemaker 400 has an outwardly hermetically sealed
housing 401 and a header 402 comprising a bushing 403 for producing the
electrically conductive connection to electrodes (not illustrated). The
electrical connection of contacts in the bushing to the printed circuit
board (PCB) 25 arranged in the housing 401 and an IC (integrated circuit)
409 is established by means of a feedthrough 405, which is arranged
between the header 402 and housing 401 and which is also hermetically
sealed outwardly. As can be seen from FIG. 29, the IC 409 has
electrically conductive connections to a battery 415, a dump resistor
416, and a capacitor unit 417 having a series of capacitors, wherein the
battery 415, the dump resistor 416, and the capacitor unit 417 are
arranged in the housing 401 of the cardiac pacemaker 400. In the
electrical connection between IC 409 and the battery 415, the battery
bridge 1 and test points 420 are arranged in parallel on the printed
circuit board 25, in such a way that the electrical connection between
the battery 415 and IC 409 is open, provided the battery bridge 1 is in
the first (open) state.

[0063] The battery bridge 1 is produced in that the cap 11 and the plunger
12 are produced separately from one another, for example, by means of a
cold forming or stamping process from a metal material. By way of
example, the ring 13 is produced by means of plastics injection molding
and, for example, consists of POM, PEEK, LCP and/or PBT. The ring 13 is
then first arranged in the continuous opening 15 in the cap 11 and is
pressed in, followed then by the plunger 12, such that a press fit is
formed between the cap 11 and ring 13, and also between the ring 13 and
plunger 12. The ring 13 thus positions the cap 11 and the plunger 12
concentrically with one another and the battery bridge 1 is in the first
(open) state.

[0064] A battery bridge 1 produced in this way is now, as illustrated in
FIGS. 5-6, arranged on a first contact face 23 or a second contact face
24 of the printed circuit board 25 and is electrically conductively
connected thereto, for example, by means of soldering. For this purpose,
a solderable coating (for example, containing at least one material of
the group comprising gold, ENIG, EPIG (electroless palladium and
immersion gold), palladium and tin) can be arranged, respectively, on the
cap 11 or the plunger 12, on the lower end face 29 of the cap 11, in the
lower region of the side face 30 of the cap 11, or on the lower region of
the side face 33 of the plunger 12, and is applied prior to the assembly
of the battery bridge 1. As a result of the soldering, the first contact
face 23 is electrically conductively connected to the cap 11 and the
second contact face 24 is electrically conductively connected to the
plunger 12.

[0065] Once the cardiac pacemaker 400 has been produced with the
electronic circuit, embodied at least in part as a printed circuit board
25, with the IC 409 and the battery bridge 1, and once all connections of
the voltage source (battery 415) and of the capacitor unit 417 and of the
dump resistor 415 have been connected to the circuit, preferably welded
thereon, the circuit is initialized or powered up in a defined manner via
the two test points 420 (power-up).

[0066] Following successful power-up, the cap 11 and the plunger 12 of the
battery bridge 1 can then be used together in a single automatable
process step by means of welding, for example, by means of laser welding,
without further material feed or removal. This process step is shown in
FIGS. 7-9. The laser beam 40 is for this purpose guided in the region of
the end face 16 of the cap 11 along the air gap 18 and provides weld
spots, such that in the region of the air gap 18 the material of the cap
11 and the material of the plunger 12 fuse with one another, form an
electrically conductive connection between the cap 11 and plunger 12, and
thus fill out the air gap 18 by a weld seam 42. The path of the electrons
from a first conductive track with the first contact face 23 via the cap
11, the weld seam 42, the plunger 12 and the second contact face 24 of a
second inductive track is illustrated by means of arrows 43 in FIG. 11.
The circuit of the printed circuit board 25 is thus permanently closed,
and the battery bridge 1 is in the second (closed) state.

[0067] In the first exemplary embodiment of a battery bridge 1 according
to the present invention illustrated in FIGS. 1-11, the height of the cap
11 corresponds to the height of the plunger 12, such that the upper end
face 34 of the plunger 12 runs flush with the end face 16 of the cap 11.
By contrast, in the second exemplary embodiment of a battery bridge 1
illustrated in FIGS. 12-13, the height of the plunger 12 is greater than
the height of the cap 11, such that the plunger 12 protrudes beyond the
end face 16 of the cap. In this exemplary embodiment, the laser beam 40
can be positioned somewhat more easily, since it can be guided laterally
of the plunger 12 along the air gap 18 (see FIG. 13). As a result of the
welding, a fillet seam is formed in the region of the air gap 18 and
electrically conductively connects the cap 11 to the plunger 12.

[0068] With regard to the first exemplary embodiment of a battery bridge 1
according to the present invention illustrated in FIGS. 1-11, in the
third exemplary embodiment illustrated in FIGS. 14-15, the inwardly
arranged plunger 12 now has a shorter height than the outwardly arranged
cap 11. The cap has, in its end face 16, a continuous opening 15, through
which the laser beam 40 is guided in order to achieve a connection
between the material of the cap 11 and that of the plunger 12. The
opening 15 in the cap 11 can also be replaced by a notch, i.e., can be
closed at least in part, wherein welding is then performed through the
notch in order to establish the electrically conductive connection to the
plunger 12.

[0069] FIG. 16 shows a fourth exemplary embodiment of a battery bridge
according to the present invention which is similar to the second
exemplary embodiment according to FIGS. 12-13. The two exemplary
embodiments differ from one another merely in the form of the cap 11,
plunger 12 and/or ring (not illustrated) 13. Whereas these elements in
the second exemplary embodiment according to FIGS. 12-13 are rotationally
symmetrical, the cap 11 of the exemplary embodiment according to FIG. 16
has a non-symmetrical form, specifically a rectangular block form.
Accordingly, the plunger also is not circular-cylindrical. The
cross-sectional shape is essentially an ellipsis here. Accordingly, the
insulator (not illustrated) also is not provided as a circular ring, but
rather as an elliptical/rectangular ring. This exemplary embodiment has
the advantage that the weld seam runs linearly, at least in part. Further
forms are also conceivable for the cap 11, plunger 12 and ring 13 of the
battery bridge.

[0070] Alternatively to the production of the contact elements by means of
a cold forming or a punching process, a fifth exemplary embodiment of a
battery bridge according to the present invention will be explained
hereinafter on the basis of FIGS. 17-23, in which the components can be
produced by means of thick-film technology, which constitutes an
established, very efficient and economical technology.

[0071] The battery bridge 101 has a first weldable metal foil 111 (first
contact element) and a second weldable metal foil 112 (second contact
element), which are arranged adjacently on a ceramic substrate
(insulator) 113, separated by an air gap 118. The thickness of the metal
foils 111, 112 can be for example 400 .mu.m, and the width of the air gap
can be for example 50 .mu.m. The metal foils 111, 112 can comprise, for
example, nickel, copper, a copper-nickel alloy and/or stainless steel or
can consist of one or more of these materials. By way of example, LTCC
(low temperature co-fired ceramic) consisting of a number of materials
(for example SiO.sub.2, glass, titanate) or HTCC (high temperature
co-fired ceramic with the primary component Al.sub.2O.sub.3) can be used
as material for the ceramic substrate 113. A tin plating/soldering
coating 114 (hereinafter soldering coating 114 for short) is arranged in
each case laterally on the battery bridge 101 and on one side surrounds
the first metal foil 111 and the ceramic substrate 113 in a U-shaped
manner and on the other side surrounds the second metal foil 112 and the
ceramic substrate 113 in a U-shaped manner. A nickel intermediate layer
115 is arranged between the soldering coating 104 and the metal foils
111, 112 and the ceramic substrate 114. As a result of the soldering
coating 114 and the nickel intermediate layer 115, an electrically
conductive connection is established from the metal foils 111, 112 to the
underside of the ceramic substrate 113.

[0072] The method according to the present invention for activating an
electronic device comprising a battery bridge 101 according to the
present invention in accordance with the fifth exemplary embodiment is
carried out similarly to the method explained with reference to FIGS. 5-9
and is illustrated in FIGS. 20-23. One difference lies merely in the fact
that, in the case of the battery bridge 101, the contact elements 111,
112 are not directly connected to the contact faces 123, 124 of the
printed circuit board 125, but instead the soldering coating 114 produces
the electrical contact to the first metal foil 111 and second metal foil
112 arranged above the ceramic substrate 113.

[0073] As illustrated in FIG. 22, in this method the first metal foil 111
additionally is not fused with the second metal foil 112 along the entire
air gap 118, but instead merely two adjacently arranged weld spots 142
are provided along the air gap 118. Alternatively, just one weld spot can
be provided, or more than two weld spots can be provided.

[0074] The path of the electrons along the conductive track with the first
contact face 123, the soldering coating 114, the first metal foil 111,
the weld point 142, the second metal coating 112, the soldering coating
114, and the conductive track with the second contact face 124 is
indicated by means of arrows 143 in FIG. 19.

[0075] FIGS. 24-25 show a sixth exemplary embodiment of a battery bridge
201 according to the present invention. This has a first contact element
211, which is L-shaped in cross-section, and a second contact element
212, which is also L-shaped in cross-section. These complementary shapes
are arranged in such a way that they supplement one another and form an
air gap 218 between the first contact element 211 and the second contact
element 212, more specifically between the opposing faces of these
contact elements 211, 212. The air gap 218 accordingly forms a step
shape. An insulator 213 in the form of an adhesive film is arranged in a
lower region of the air gap 218 and by way of example is strip-like. The
contact elements 211, 212 are preferably produced by means of cold
forming, MIM (metal injection molding), milling, or etching, and the
insulator 213 is produced from an acrylate adhesive film. The arrangement
on a printed circuit board 225 having a first contact face 223 and a
second contact face 224 is provided in such a way that the first contact
element 211 is directly soldered to the first contact face 223 and the
second contact element 212 is directly soldered to the second contact
face 224. Similarly to the exemplary embodiment of the battery bridge
111, a connection of the two contact elements 211, 212 and the second
(closed) state of the battery bridge 201 is achieved by two weld spots
242.

[0076] The seventh exemplary embodiment of a battery bridge 301 according
to the present invention illustrated in FIGS. 26-28 is similar in terms
of structure to the battery bridge 201 illustrated in FIGS. 24-25. The
first contact element 311 and the second contact element 312 also each
have a complementary form that is L-shaped in cross-section, but in which
an air gap 318 is formed. The insulator 313, formed, for example, as an
adhesive film, also has here a strip shape in cross-section, preferably
with a step. The battery bridge 301 also has a rectangular annular
housing 316, which annularly surrounds the first contact element 311 and
the second contact element 312. The first contact element 311 and the
second contact element 312 protrude beyond the housing 316 on the
underside so as to be able to establish proper contact with corresponding
contact faces of a printed circuit board. In the closed state of the
battery bridge 311 illustrated in FIG. 28, the first contact element 311
and the second contact element 312 are electrically conductively
connected to one another via weld spots 342.

[0077] The advantages of the above-presented SMT-capable battery bridges
1, 101, 201, 301 according to the present invention and the
above-explained method according to the present invention for activating
an electronic device lie in particular in the ability to automate the
initialization and closing process of the circuit. A greater process
reliability and a reduction of the run-through time for the power-up can
thus be achieved. It is not necessary to remove material and it is also
not necessary to hold down contacts. With a battery bridge 1, 101, 201,
301 that can be welded in an automated manner in accordance with the
present invention, the manufacturing flow can be significantly
simplified.

[0078] It will be apparent to those skilled in the art that numerous
modifications and variations of the described examples and embodiments
are possible in light of the above teachings of the disclosure. The
disclosed examples and embodiments are presented for purposes of
illustration only. Other alternate embodiments may include some or all of
the features disclosed herein. Therefore, it is the intent to cover all
such modifications and alternate embodiments as may come within the true
scope of this invention, which is to be given the full breadth thereof.
Additionally, the disclosure of a range of values is a disclosure of
every numerical value within that range.